Method for Producing a multiple-layer label and device for implementing said method.
The invention relates to a method for manufacturing a multiple-layer tag, in which two webs of material are brought together by means of two parallel laminating rollers, and in which portions of a coating web arrive on a supporting web, spaced apart from one another. The invention furthermore relates to a device for implementing this method.
A method and a device of the type described hereinabove is described in WO 86/05302. In FIGS. 18 and 19 of this document it is shown how two webs of material are brought together by means of two laminating rollers and are joined together. Portions composed or printed conductor foils, each with a resonant electrical circuit for the purpose of protecting goods provided with the tag, in that when not deactivated, the resonant circuit triggers an alarm signal, are previously applied at a distance apart from one another to these webs of material.
The positioning of portions on a supporting foil is a very expensive phase of manufacturing, and limits the speed of production in mass production of tags. Furthermore, the manipulation of the cut-out portions necessary often leads to breakdowns.
In order to avoid such breakdowns, it is known from U.S. Pat. No. 5,059,950 to bring together a supporting web and a coating web such that the portions configured as security elements are spaced at the same distance apart on the supporting web as on the coating web provided with these portions. After the two webs of material have been brought together, they must be detached together in order to obtain one tag with one portion with each separation. The advantage of such a method is that only right at the end are there individual tags, so positioning of the portions relative to the supporting web is no longer necessary. However, it is disadvantageous that the portions are inevitably spaced at exactly the same distance apart on the supporting web as on the coating web. If it were desirable to produce tags which are larger than the portions, a coating web would have to be used where the security elements forming the portions were spaced apart, which would be a waste of material with respect to the coating web and would make changing the spacings possible only if the coating web were to be changed correspondingly.
The object of the invention is to further develop a method of the type described in the introduction such that tags can be manufactured particularly easily, rapidly and reliably, which tags have a larger area than a portion provided on them, in particular a security element. Furthermore, a device for implementing this method will be developed.
The problem described firstly is solved according to the invention in that the coating web is alternately advanced to the laminating rollers or to a pair of rollers connected in front of these at the circumferential speed of the pair of rollers, then a portion of the coating web advanced is detached, and lastly the coating web is stopped for a defined period of time.
Using this method, the manipulation and positioning of individual portions on the supporting web, which is time-consuming and prone to causing numerous breakdowns, is eliminated. In exactly the same manner as according to the method described previously in U.S. Pat. No. 5,059,950, the portions can be continuously fed to the supporting web by means of the coating web, and need to be detached from the coating web only directly before or during lamination. In spite of using this method, it is possible to change the spacings between the portions on the supporting web in that the coating web can be stopped for a longer or shorter period and in this way the supporting web can advance for a longer or shorter distance. In this way the method according to the invention is just as reliable and can be carried out just as quickly as that according to U.S. Pat. No. 5,059,950 described herein, but is variable in a manner similar to WO 86/05302.
When the method is implemented, the operations phase of applying an adhesive layer is eliminated when a supporting web with an adhesive layer facing the coating web is used.
It is also advantageous when, in accordance with another further development of the method, the adhesive layer applied to the supporting web is temporarily covered with a protective foil and this is removed before the bringing together of the supporting web and the coating web. In this way the adhesive layer remains protected from unintentional adhesion for as long as possible. Re-use of the protective foil removed is possible after the coating web has been applied.
Where a plurality of rows of portions are to be applied to a wide supporting web which is later to be separated into a plurality of individual webs of tags, the spacing of the portions can vary from row to row when the coating web is divided into two or more longitudinal strips by a fanning means before being applied to the supporting web.
The problem described secondly, that is to say the provision of a deice for implementing the method according to the invention, is solved in accordance with the invention with a device which has two parallel laminating rollers for bringing together two webs of material, in that in front of the parallel laminating rollers there is arranged an advancing means driven by a servo-motor, which is set up for alternate stopping and driving of the coating web at the speed of the supporting web.
Such a device allows the advancing of the coating web to be interrupted for defined periods of time in a simple manner, and thereby the changing of the spacings of the portions on the supporting web in a defined manner. In this way the device according to the invention makes it possible to change the spacings of the portions on the supporting web just by different settings of the device and by changing of the cutting tool. In spite of this possibility for adjustment, the device according to the invention is constructed in a very simple manner and is easy to operate as no separate portions have to be manipulated and positioned on the supporting web.
The individual portions of the coating web can be separated from the coating web in a single operating phase together with lamination when one laminating roller is equipped with at least one stamping blade which projects from the contour of the laminating roller exclusively for detaching the coating web applied to the supporting web.
The advancing means does not need to accelerate the entire coating web when advancing a portion of the coating web towards the laminating rollers, when, for tensioning the coating web, in front of the advancing means a roller partly looped around by the coating web is arranged on a pendulum. Slack is obtained by means of the roller on the pendulum, from which the advancing means takes up the area of the coating web currently required. Furthermore, in this way the coating web can be payed out from a stock roll at a constant speed.
An insufficient length of slack in the coating web or excessively fast paying out of the coating web from the stock roll can be prevented using very simple means, when in accordance with another development of the invention, the pendulum has control means for controlling a feed drive connected in front of it for paying out the coating web from a stock roll.
When the device is configured for cutting the coating web into a plurality of strips running parallel to one another, a fanning means for spreading out the strips can be arranged between the feed drive and the pendulum. It is then possible not only to change the spacing of the portions in the direction of movement of the supporting web, but also the spacing of the portions at right-angles thereto.
Unintentional gluing together of the two webs of material before reaching the laminating rollers can be prevented in that a separating element separating the coating web from the supporting web until they are fed into the laminating rollers is arranged on the feed-in side of the laminating rollers. This separating element can, for example, be configured as a separating plate or be composed of separating rods.
Instead of separating the portions from the coating web only after applying them to the supporting web, the operational phase of separation can also be carried out directly prior to this. A device configured for this is characterised in that an additional cutting roller for separating the portions from the coating web is assigned to the laminating roller for advancing the coating web, and in that the laminating roller is configured for transporting the portions to the supporting web on the other laminating roller.
The separated portions must be retained on the cutting roller after separation so that can be fed to the supporting web without changing their position. To do this, the portions could be held on the cutting roller by a partial vacuum. The cutting roller is particularly simply configured when the laminating roller for advancing the coating web is provided with a pressing means covering its lateral surface between the cutting roller and the laminating roller.
Separation of the portions from the coating web is inevitably always in exactly the right area, so when the portions are security elements there is no risk of them being destroyed by being cut in the wrong place if, in accordance with a further development of the invention, in order to control the advancing means a measuring means for recognising an end of a portion on the coating web is arranged in front of the laminating rollers.